Hubble telescope unveils never before seen ‘monster stars’

An international team of scientists using the NASA/ESA Hubble Space Telescope has combined images taken with the Wide Field Camera 3 (WFC3) with the unprecedented ultraviolet spatial resolution of the Space Telescope Imaging Spectrograph (STIS) to successfully dissect the young star cluster R136 in the ultraviolet for the first time [1].

The image shows the central region of the Tarantula Nebula in the Large Magellanic Cloud. The young and dense star cluster R136 can be seen at the lower right of the image. This cluster contains hundreds of young blue stars, among them the most massive star detected in the Universe so far. Using the NASA/ESA Hubble Space Telescope astronomers were able to study the central and most dense region of this cluster in detail. Here they found nine stars with more than 100 solar masses. CREDIT NASA, ESA, P Crowther (University of Sheffield)

From the ESA/HUBBLE INFORMATION CENTRE

Hubble unveils monster stars

R136 is only a few light-years across and is located in the Tarantula Nebula within the Large Magellanic Cloud, about 170 000 light-years away. The young cluster hosts many extremely massive, hot and luminous stars whose energy is mostly radiated in the ultraviolet [2]. This is why the scientists probed the ultraviolet emission of the cluster.

As well as finding dozens of stars exceeding 50 solar masses, this new study was able to reveal a total number of nine very massive stars in the cluster, all more than 100 times more massive as the Sun. However, the current record holder R136a1 does keep its place as the most massive star known in the Universe, at over 250 solar masses. The detected stars are not only extremely massive, but also extremely bright. Together these nine stars outshine the Sun by a factor of 30 million.

The scientists were also able to investigate outflows from these behemoths, which are most readily studied in the ultraviolet. They eject up to an Earth mass of material per month at a speed approaching one percent of the speed of light, resulting in extreme weight loss throughout their brief lives.

“The ability to distinguish ultraviolet light from such an exceptionally crowded region into its component parts, resolving the signatures of individual stars, was only made possible with the instruments aboard Hubble,” explains Paul Crowther from the University of Sheffield, UK, and lead author of the study. “Together with my colleagues, I wouldlike to acknowledge the invaluable work done by astronauts during Hubble’s last servicing mission: they restored STIS and put their own lives at risk for the sake of future science!” [3]

In 2010 Crowther and his collaborators showed the existence of four stars within R136, each with over 150 times the mass of the Sun. At that time the extreme properties of these stars came as a surprise as they exceeded the upper-mass limit for stars that was generally accepted at that time. Now, this new census has shown that there are five more stars with more than 100 solar masses in R136. The results gathered from R136 and from other clusters also raise many new questions about the formation of massive stars as the origin of these behemoths remains unclear [4].

Saida Caballero-Nieves, a co-author of the study, explains: “There have been suggestions that these monsters result from the merger of less extreme stars in close binary systems. From what we know about the frequency of massive mergers, this scenario can’t account for all the really massive stars that we see in R136, so it would appear that such stars can originate from the star formation process.”

In order to find answers about the origin of these stars the team will continue to analyse the gathered datasets. An analysis of new optical STIS observations will also allow them to search for close binary systems in R136, which could produce massive black hole binaries which would ultimately merge, producing gravitational waves.

“Once again, our work demonstrates that, despite being in orbit forover 25 years, there are some areas of science for which Hubble is still uniquely capable,” concludes Crowther.

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Notes

1] R136 was originally listed in a catalogue of the brightest stars in the Magellanic Clouds compiled at the Radcliffe Observatory in South Africa. It was separated into three components a, b, c at the European Southern Observatory , with R136a subsequently resolved into a group of eight stars (a1-a8) at ESO, and confirmed as a dense star cluster with the NASA/ESA Hubble Space Telescope after the first servicing mission in 1993.

[2] Very massive stars are exclusive to the youngest star clusters because their lifetimes are only 2-3 million years. Only a handful of such stars are known in the entire Milky Way galaxy.

[4] The ultraviolet signatures of even more very massive stars have also been revealed in other clusters — examples include star clusters inthe dwarf galaxies NGC 3125 and NGC 5253 . However, these clusters are too distant for individual stars to be distinguished even with Hubble.

More information

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

The results were published in the paper “The R136 star cluster dissected with Hubble Space Telescope/STIS. I. Far-ultraviolet spectroscopic census and the origin of Heii λ1640 in young star clusters” inthe Monthly Notices of the Royal Astronomical Society.

43 thoughts on “Hubble telescope unveils never before seen ‘monster stars’”

So Leif, if these stars are so super massive (I believe it), and their future is to be black holes, which ultimately can collide in pairs, and emit Einstein Waves; what is it that prevents coupled pairs of these UV stars from emitting such waves. Do they need to be Relativistic in speeds to do so, or is just plenty of mass enough ??

Well Leif, I still don’t have a good grasp, of just how LIGO is recording such fantastically small displacements; but I have no doubt that they are, and I think I understand the filtering process that selects what the candidate detected event must be, which is way beyond clever.

But it sounds like everybody will have to have a LIGO antenna in their garage, so we can all listen in to the goings on.

I imagine you guys are having a ball right now, contemplating what the future of Gravitational Astronomy may be like, as LIGO sensitivity and S/N ratio improves.

The obstacles LIGO has to deal with are significant, and sometimes not what you would expect. I took my daughter to the LIGO Hanford open house last weekend, and was amused to discover one of their problems is tumble weeds. They need access to the instruments at the end of the 4KM legs of the detector, but the legs serve as tumble weed collectors and the roads get blocked. They have a machine on-hand to collect and bale the tumble weeds. It’s always something….

– So called ‘BH’ are suppose to be collapsed ‘super’ massive neutron (all electrons and protons fused into neutrons) stars, so they are not ‘black holes’ but super-massive black bodies ‘SMBB’s.
– When those two SNBBs crushed, due to their mass and orbital velocities a huge amount of kinetic energy should have been released in form of heat (electromagnetic energy), but since it can not escape the event horizon (EH), it has to be contained within it or converted to extra mass. Thus, the resultant SMBB should be more massive than the sum of its two components, or the space within EH is supper ‘hot’ whatever that might mean.

A bit of perspective on the sensitivity of LIGO: It’s generally accepted that the sensitivity of a conventional resistance strain gage, measured with conventional electronics, is limited to about 1 microstrain (10^-6). That’s taking a seventeen mile long wire (a million inches), stretching it one inch, and measuring the change in resistance. LIGO measured a strain of about 10^-21 when the black holes combined. That’s been described as taking a wire the length of the earth’s orbit around the sun, and stretching it the diameter of a hydrogen atom. Now it may likely be possible to improve that sensitivity, but it will certainly take some ingenuity.

“””””….. LIGO measured a strain of about 10^-21 when the black holes combined. …..”””””

So Tom, did LIGO actually measure a ‘strain’ in the sense of a solid material stretching E-21 of its original length or did it just measure a ‘displacement’ of one pseudo rigid mass relative to another.

I got the impression that the optical mirrors of the interferometer were the actual sensors, in that they moved relative to each other perhaps by E-21 of their separation. Well I suppose the GR geeks would say that the space between them stretched by that fraction as the wave went through like a could of surfers riding a curl.

I’ll have to get with the program, and print out my copy of the paper and study it better. The ‘L’aser part is evidently just a resonant cavity within the confines of the Michelson Interferometer arm.
That could be viewed as simply a round trip multiplier, as if the beam starts from one interferometer mirror, and rattles around inside the cavity, before exiting after having gone a thousand times around the loop.

It seems to me that somehow the optical path length change has to get multiplied up, to become ‘visible’.

A parallel plate Fabry-Perot resonator is unstable, because if the plates aren’t exactly parallel, the beam walks off the edge of the mirror.

But if you had two quite big (and massive) mirrors you could actually make the beam go back and forth a hundred times walking sideways, until you got to a hole in the mirror coating to let the beam out. Then the total transit time of the beam would change by 100 times the physical length change.

Well I would like to have an optical diagram of the whole optical path setup, so I can see what is really going on.

But I don’t see them measuring an actual strain in some material. The optical path is mostly in vacuum, so nothing except space is actually being strained.

Well almost all cameras are black and white, in that the silicon CMOS or maybe CCD simply measures electric charge converted from photons via the Einstein process.
But real spectral information can be obtained by spectrally selective filtering.

So yes the visual hue is inferred from a limited spectral measurement, but that is the nature of color vision. The color is all in your head; it isn’t physically real.

You don’t see any green stars, because there is NO black body Temperature, at which the dominant wavelength with normal vision happens to be in the (human) green region. Who the heck knows what a lobster sees when looking at a New Zealand green shelled mussel ??

Counter intuitive garbage is what black holes are. If such linear holes existed there would be no universe, given black holes are eternal, there must have been one right at the start, yet inflation theory..

It just goes more stupid as time goes by.

Now they claim “near infinite” rather than infinite but what the astrophysicists cannot seem to understand is near infinite is actually infinity too, as to be near infinity means to constantly follow infinity in order to be close to it.. to infinity.

So these clowns are so far down the illogical mathematics hole that they make such stupid statements.

This borders on nonsense, in vicinity of the black holes the space is so distorted by huge gravity forces, that ‘6 miles’ means nothing, not that I believe that there is such a thing as a singularity black hole.
However there are super-massive black bodies SMBBs as remnants of the collapsed neutron stars. Those could have a radius of 6 miles but unlikely to that of the solar system.

R136a1 is actually larger than a star can theoretically get. If anything, it must have been a merger of two or three giant stars.

When it explodes as a supernova, it won’t actually explode at all. It will be just collapse directly into a black hole. There are only a few stars that we know about it that are large enough to get to this limit.

But our favourite star other than the Sun, still has to be Eta Carinae, also large enough to form a black hole after it supernovas any day now (or a few thousand years anyway). NASA recently released an animation of Eta Carinae and its companion star which shows the hellish conditions near these stars.

Perhaps we should be looking at this more like the beginnings of what will be a central core for a new galaxy. As the central mass interacts would there necessarily need to be a massive black hole to hold it all in place?

So according to the pundits some billion years ago the universe started as a singularity that exploded into an expanding universe. This big star loosing one Earth mass a month would have been small a long time ago if it was old. Were is all this stuff coming from to form these gigantic young stars? Maybe all this stuff after 4 billion years or so just decided recently to get together, perhaps there is a better explanation of how our universe works. Call me a cynic but the big bang idea does not make sense.

Based upon big bang acoustics many astrophysicists believe the universe is infinite and infinitely old as in has always been in existence. This does, of course, not match up well with the conventional concept of a bigbang 13.5 billion years ago which can be tracked back to some sort of singularity inflating into everything we have now. But I guess the math works even if it makes no sense.